Problem: $ { \left[\begin{array}{rr}{0} & {3} \\ {2} & {3} \\ {-1} & {1}\end{array}\right]+\left[\begin{array}{rr}{-2} & {1} \\ {4} & {0} \\ {2} & {0}\end{array}\right] = {?} } $
Answer: To find the sum of two matrices, add the corresponding items between each matrix. ${\left[\begin{array}{rr}{0}+{-2} & {3}+{1} \\ {2}+{4} & {3}+{0} \\ {-1}+{2} & {1}+{0}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{-2} & {4} \\ {6} & {3} \\ {1} & {1}\end{array}\right]}$